If you’re committed to working out, you may wonder how to extend workout stamina and shorten muscle recovery time. There are plenty of pre-workout supplements on the market, but it can be challenging to figure out which might be best for you. One option for athletes is a nitric oxide supplement — capsules or drinkable powders that help boost nitric oxide production in your body. Enhanced nitric oxide levels have been shown to speed recovery time and lead to longer, more intense workouts.1 27 28
But are these supplements legit? Do they really provide what they promise? Read our guide to find out about their ingredients, effectiveness, cost, and more.
If you don’t have time to read the whole guide, take a look at our Top 5 list of recommendations below.
Type Zero's supplement combines high doses of several nitric oxide-boosting ingredients in five delicious flavors.
Type Zero makes Vegan- and keto-friendly supplements without artificial colors, flavors, or sweeteners. Instead it includes high doses of L-citrulline, L-arginine, betaine, beetroot extract, GABA, and N-acetyl L-tyrosine for optimal performance and cognitive enhancement.
Shop on TypeZero.com and receive 15% off with code INNERBODY15.
At Innerbody Research, we extensively test each health service or product we review, including nitric oxide boosters. Our team purchased and tested top products to determine which ones are superior, which ones could benefit specific individuals, and which ones to avoid. That testing experience allows us to relay to you critical information about taste, mixability, shipping, and customer service. We were also able to see how these supplements made us feel and whether they had any effect on our exercise regimen. Our testers aren’t professional athletes or trainers but instead regular folks who intend to get a healthy amount of exercise and eat well.
To bolster our team’s experiences with a deeper understanding of the topic, we devoted nearly 500 hours to studying more than 100 scholarly articles pertaining to fitness and nitric oxide. Additionally, like all health-related content on this website, this review was thoroughly vetted by one or more members of our Medical Review Board for accuracy. We’ll stay on top of any developments in the NO landscape to ensure our recommendations remain current.
Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions about staying healthy and living healthier lifestyles.
Image by Innerbody Research
Increasing nitric oxide may have several potential benefits for consumers, so in evaluating which supplements were the best, we looked at five key areas that would affect most people, regardless of their reasons for seeking a supplement. Those key areas were:
Effectiveness bore the most weight in our considerations, as you’re less likely to take a supplement if you know it won’t work. But safety is a close second in this category, considering the effect that increased nitric oxide can have on blood pressure. While we can speak to taste and mixability after having tried these supplements for ourselves, taste is subjective. Cost was less important here, as so many of these supplements cost a similar amount. Finally, while customer service and convenience aren’t deal breakers for many, they may tip you in one direction or another if you’re torn between options.
Winners: Type Zero Clean Stim-Free Pre-Workout + Nitric Oxide Booster and Gorilla Mode Nitric
There are some ingredients that you’ll repeatedly notice in nitric oxide supplements. Ingredients like arginine, citrulline, and beetroot are well known for boosting nitric oxide levels.2 Some supplements also include proprietary blends, patented boosters, and other nutrient-rich food extracts to enhance nitric oxide production further, though the science on these is less comprehensive.
One of the reasons we regard Type Zero’s nitric oxide booster as the best overall choice for most people is that it’s the only product in our guide to combine high doses of L-citrulline, L-arginine, and beetroot extract. It also includes betaine, which has been shown to reduce homocysteine levels in clinical studies, making this a good choice for people looking to manage high blood pressure and their risk of cardiovascular disease without a prescription (though it would be imperative to speak to your doctor before relying on this or any nitric oxide booster for heart health).12
Gorilla Mode Nitric is a close second to Type Zero only because it’s a more targeted supplement with an ingredient profile tuned toward exercise performance. It’s the only option on our list to include creatine, a well-regarded workout supplement. It also offers sodium and potassium as electrolytes to fuel muscle activity.
Winner: HumanN SuperBeets Sport
While many ingredients in nitric oxide supplements, like L-citrulline, appear to be effective in clinical trials, this doesn’t necessarily mean they are safe to consume.5 Just like with any supplement, you should begin a nitric oxide booster with caution and pay attention to how your body reacts to it. Pay attention to warning labels and consult your doctor.
To improve safety concerns, we look for supplements with ingredients that are produced in FDA-regulated facilities and that undergo third-party testing for at least one parameter. Bulk Supplements nearly took this category, thanks to its large array of single-ingredient supplements, but we ultimately gave it to HumanN’s SuperBeets Sport.
Compared to L-arginine and L-citrulline, beetroot juices, powders, and extracts are still effective, but they’re slightly less effective than those alternatives. That means they should still work for many people, but they’ll pose less of a risk to anyone with cardiovascular concerns. Notably, HumanN manufactures its products in cGMP-certified facilities, subjecting them to third-party testing for contamination and dose and ingredient accuracy.
HumanN also recently updated its formula and renamed it SuperBeets Sport from its previous name, BeetElite. The change to the formula was subtle — adding 500mg of coconut water powder per dose. Coconut water provides two key benefits to what is essentially HumanN’s beet-based pre-workout. The first is added hydration, which studies show coconut water powder can provide.25 The second is potential renal protection, as it’s also been shown to reduce the incidence of kidney stones in rats (more research needs to be done on humans before confirming this benefit).26
Type Zero and HumanN offer very different products with disparate goals for taste. Type Zero’s nitric oxide booster bills itself as a pre-workout and fits into a part of the marketplace that expects fun, fruity flavors. Compared to most competitors offering similar taste experiences, Type Zero blows them out of the water. It relies on stevia as the lone sweetener in most of its products, including its NO booster, though the company sometimes uses erythritol, as well.
HumanN’s product is more associated with the health and wellness market than with the fitness market, and its ingredients and flavor reflect this. Like Type Zero’s NO booster, this product mixes extremely well into water. At first, we saw a little clumping, but that largely dissipated with a little extra stirring. Its flavor is a pretty intense mix of beet and cherry, and the two complement each other much more than our testers had expected.
Winners: Bulk Supplements
Bulk Supplements is often a safe bet for budget-conscious consumers. The company typically offers vegan-friendly ingredients whenever possible, and its products are third-party tested. When you look at the nutritional label for most of its products, you’ll find relatively conservative serving sizes, which can inflate their value if you calculate the cost per serving. But its cost per gram of individual ingredients is often much lower than that of other companies. And the difference in cost per serving across nitric oxide boosters is so vast that you could take ten times the recommended dose and still save money (with your physician’s consent, of course).
There really isn’t a second place in this category, either. Costs per serving for the other companies in this guide range from $1.50 to $2.00. For Bulk Supplements L-arginine or L-citrulline, the costs average around $0.05 per serving, depending on your particular serving size and the amount you buy with each purchase. On top of this, you also can save 5% using discount code INNERBODY5 when you purchase.
In measuring customer service, we look at things like website design, customer support infrastructure, dosage, and shipping logistics. The differences among companies in this category are subtle, but they can significantly impact your experience.
For example, HumanN and TypeZero utilize chat interfaces on their websites. This makes it pretty quick and easy to get answers to specific product or service questions. The website for Gorilla Mind (the maker of Gorilla Mode Nitric) appears to have a similar feature, but it’s operated solely by a bot that isn’t terribly helpful with specifics. And Bulk Supplements only has an email form pop up when you click what appears to be a chat option.
Adding to its customer service experience, HumanN has a phone number you can call to talk to product specialists during hours of operation. And it provides faster shipping than any of the competitors on our guide.
In order to get a clear sense of how the top nitric oxide boosters compare, we've put together a handy chart. Prices in the chart reflect one-time purchases before any discounts for bulk or subscription programs would apply.
Special Offer from Type Zero: 15% OFF with code INNERBODY15
Nitric oxide (NO) is a colorless gas that serves a specialized role in the body as a signaling molecule responsible, in part, for vasodilation. This means that it increases blood flow throughout your body by relaxing blood vessel muscles, which lowers blood pressure and can help red blood cells deliver more oxygen to your body. Your body uses antioxidants like vitamin C and nitrates (found in leafy green vegetables and other foods) to produce nitric oxide. In addition to circulation, nitric oxide impacts the function of other bodily systems, including the immune and musculoskeletal systems.
People who smoke, don’t exercise regularly, have high cholesterol, or eat a high-fat diet may have lower nitric oxide levels. This can cause issues like:
Eating foods rich in nitrates, exercising regularly, and taking probiotics or antioxidants can help boost nitric oxide levels naturally. Some people opt for nitric oxide supplements, which use various ingredients to increase levels of nitric oxide production.
Nitric oxide supplements, or NO boosters, don’t contain nitric oxide — instead, they contain ingredients that your body can use to produce nitric oxide. In studies, the efficacy of these ingredients is often tied to changes in blood pressure as resulting NO relaxes blood vessels.29 Studies also look at things like peak power output during weightlifting sessions and VO2 max or gas exchange threshold in intense cardio situations.
Some popular ingredients in nitric oxide supplements include:
Thanks to its role in supplements designed to address male sexual dysfunction, L-arginine has undergone a significant amount of research.3 Among the typical ingredients studies have shown to affect blood pressure, L-arginine has had the most profound effect. Yet in a study from 2011 measuring VO2 max in trained cyclists, arginine had no meaningful effect.4 Evidence suggests L-arginine may perform better in lesser-trained individuals. Typical doses in studies range from 1.5g-25g/day, with effects noticeable even at the 1.5g end of the spectrum.
L-Citrulline is often administered alongside or in lieu of L-arginine because of its ability to convert to L-arginine inside the body. Doses around 6g have been popular in studies and have resulted in blood pressure effects nearly as potent as those seen with L-arginine.5 One test utilizing 8g doses with weight lifters saw an increase in power and a decrease in muscle soreness after the workout.6
Beetroot supplements typically come in just behind L-arginine and L-citrulline in their ability to affect blood pressure.7 Comparing beetroot supplements can be difficult, as some use beetroot powder, while others use an extract, and still others use both. And much of the literature in support of beetroot utilized beetroot juice, including a 2018 systematic review that suggests beetroot juice supplementation “should be promoted” as a way to control blood pressure.8
Ultimately, while beetroot extract or powder appears promising, more research on those specific forms of the supplement is necessary.
L-Norvaline hasn’t been as actively studied for its role in NO production as L-arginine or L-citrulline, but recent animal research indicates potential.9 Unfortunately, it’s not as widely available as those other amino acids, and it’s usually more expensive as a result. There have been reports about potential toxicity, as well, but recent analyses suggest those were overblown.10
Clinical research involving dialysis patients showed that betaine could regulate blood pressure, albeit less intensely than other NO boosters.11 Additional clinical research found that betaine can lower homocysteine levels, reducing cardiovascular risk.12 That makes it a smart addition to NO boosters for those with both mild cardiovascular issues and a green light from their doctor to try a booster.
Pine bark extract is used in NO boosters for a chemical compound called polyethylene glycol. The only credible studies implying its efficacy in NO production administer it in conjunction with L-arginine and grape seed extract, making it difficult to ascertain its true value.13
These compounds have been investigated in various studies related to:
While that research is somewhat limited, several studies show a link between nitric oxide supplements and increased health benefits. For example, a clinical trial found that one beetroot-based supplement significantly reduced blood pressure in patients with hypertension.14
Other health benefits are not so clear-cut. For example, researchers have concluded that nitric oxide is vital in producing erections, but human studies of L-arginine supplementation with erectile dysfunction patients are inconclusive. Animal studies have shown promise.15
Similarly, researchers found conflicting results in a review of studies looking at various NO boosters.1 An interesting pattern emerged in which more heavily trained participants showed less of an increase in performance than lesser-trained individuals.16 This implies that people who are more out of shape have more to gain from using an NO booster. But there are other studies in which well-trained athletes perform a bit better with specific NO donors like L-arginine.17
Nitric oxide supplements are popular among athletes because of their ability to help with stamina, particularly as it pertains to a person’s gas exchange threshold (a measure of oxygen intake and CO2 output that speaks to exertion levels). Basically, if you do anything that gets your breathing rate up, a nitric oxide supplement can improve your endurance. This is true for marathon runners and bodybuilders alike.
But as mentioned earlier, multiple studies show advantages for untrained individuals that are greater than those for people in Olympian shape. If you’re just getting back into the gym after a long hiatus, and you find yourself reeling during small bouts of cardio, a nitric oxide booster might help.
In addition to their benefits for athletes, nitric oxide supplements may be helpful for people who live with conditions like high blood pressure, high cholesterol, or other issues that impact the cardiovascular, respiratory, circulatory, and immune systems — but you must speak with your doctor first. More research is needed to further substantiate these claims.
Nitric oxide supplements are designed for healthy adults. Their capacity to affect blood pressure is the main concerning side effect, especially if you take nitric oxide supplements alongside medication designed to address cardiovascular issues (such as erectile dysfunction medications).
If you take regular medications or live with a chronic condition, a nitric oxide booster may not be a good idea for you. Avoid them at first until you speak with a doctor. Those who are pregnant or nursing should also avoid these supplements. Some specific types of medication (like those that include nitrates) can lead to adverse reactions when taking nitric oxide supplements, such as an unsafe drop in blood pressure. If you take medicine for chest pain or erectile dysfunction, avoid these supplements until you consult a doctor.
We think it’s always a good idea to check with your doctor or nutritionist before starting a nitric oxide supplement. (By the way, this is generally true for all supplements.)
The safety of any nitric oxide booster has a lot to do with its specific ingredients. In many ways, the more effective an NO booster is, the more risks it presents to those with blood pressure issues. That’s because of the well-established relationship between NO and blood pressure. When NO signals the muscles that control blood vessels to relax, those vessels allow blood to flow more freely, effectively dropping your blood pressure.
Many nitric oxide supplements are marketed as pre-workouts because of their potential to increase exercise performance. These supplements will often contain multiple ingredients that have scientific research supporting their ability to increase NO production. There is not enough research into how these various ingredients might interact with one another, specifically whether their abilities will create something stronger or weaker than the sum of its parts. These mixes also have the potential to be riskier, but it’s worth noting that we haven’t found a single supplement that uses doses as high as those applied in most studies for common NO donors. Since a majority of those studies reported only small quantities of minor side effects, the likelihood that a supplement containing less of the same ingredients will be safe is relatively high.
Pre-workout mixes also typically contain sweeteners, colors, and flavors that can make them generally less healthy. Among the supplements in our guide, only Gorilla Mode Nitric contains such artificial ingredients, the most hazardous of which is the sweetener sucralose. If avoiding artificial sweeteners is important to you, there are plenty of naturally sweetened alternatives.
Best overall and best tasting
Type Zero doesn’t have as large a catalog as many of its competitors, but what it does make, it makes well. In our testing, this company’s formulas have consistently offered some of the best dosages and the best flavors we’ve encountered. Its Clean Stim-Free Pre-Workout + Nitric Oxide Booster is no exception.
The formula contains a nearly study-level dose of L-citrulline, as well as a dose of L-arginine that aligns with some successful human studies. It rounds out the formula with betaine and beetroot extract, along with a few popular nootropic ingredients, including GABA and N-acetyl L-tyrosine.18
Here’s a look at the full ingredients list:
The company also offers a capsule-based NO booster that lacks some of the nootropic pre-workout ingredients found here and provides lower doses overall. In our opinion, there is no choice between the two; the Clean Stim-Free Pre-Workout + Nitric Oxide Booster powder is far superior.
Type Zero Clean Stim-Free Pre-Workout + Nitric Oxide Booster is our out-and-out winner for taste. This has been true for pretty much every category in which one of its supplements has made an appearance. (Any of its flavors with mango in them are particularly enjoyable if you like mango.) The flavors available for its NO booster are:
Type Zeros products typically mix well into water, and that holds true for its NO booster. The mix isn’t as seamless as you’d get with one of the single-ingredient amino acids from Bulk Supplements, each of which become almost undetectable in water, but it’s still a great choice.
Unlike Gorilla Mind and Bulk Supplements, Type Zero doesn’t offer any kind of discounts for bulk purchases, and it doesn’t offer a subscription system either. That means there’s one price to worry about with its NO booster. A single jar containing 21 servings costs $35.95. Shipping is not free, no matter how much you spend, but it starts at just $5 per order for standard ground shipping. There’s a 30-day window for returns, but the products must be unopened.
Compared to other companies, Type Zero’s pricing, shipping, and return policies are weak points. In the future, we’d like to see them offer money-back guarantees like HumanN and subscription platforms to take the stress out of reordering and offer some kind of discount for recurring business.
Best from beetroot
Image by Innerbody Research
Nearly every product in HumanN’s catalog is based around the beet. Its SuperBeets line is the heart of its lineup, but you can get double the beetroot powder of regular SuperBeets for an extra $5 by opting for its SuperBeets Sport. That’s our pick for the best beetroot-based NO booster.
The beetroot dose in this product is somewhat unclear, so we reached out to the company for clarification. It wouldn’t give us exact numbers, but the total serving size is 10.5g, and company reps told us that all of the non-beetroot ingredients totaled less than 1g and that the newly added coconut water powder is a 500mg dose. That leaves you with somewhere between 9g and 10g of beetroot powder. Compared to clinical research that showed efficacy with 15g of a similar powder, we believe the >9g dose will be sufficient for many people.
Here’s the complete ingredient breakdown:
Image by Innerbody Research
The same weekend that our testing team tried HumanN BeetElite, the company updated its formula and changed the name to SuperBeets Sport. We’ve had coconut water and products containing coconut water powder in the past, so we’re confident that our tasting and mixing experience can speak to what you might expect from HumanN’s new formula.
When we mixed our first glasses of BeetElite, testers had some concerns about its texture. Swirling it in the glass left a few granules along the side. But a little more mixing seemed to get rid of those. While drinking it, we saw a few small clumps on the bottom, so we gave it another stir, and those dissolved as well. So, it will mix well into plain water, but you should be thorough in your mixing.
SuperBeets Sport’s taste will be somewhat divisive. The black cherry flavor is a very nice complement to the natural beet taste, and the stevia content is just high enough to add a pleasant sweetness without detracting from other flavors. There will undeniably be some who find its taste too “healthy,” but our testers agreed that the flavor grows on you as you continue to drink it.
Like Type Zero, HumanN doesn’t offer bulk or subscription discounts on its SuperBeets Sport supplement. It does offer bulk and subscription options on other products in its catalog, which is frustrating when this is clearly one of its best options. You can get 15% off your first order when you sign up for the mailing list, but that’s the only break in price you’re liable to get.
Shipping is a flat $8.95. The only way to get free shipping from HumanN is to spend more than $75 or use its subscription system, but that’s not available on this product.
The brightest aspect of HumanN's logistical side is its money-back guarantee. There are few such guarantees in this market, with most companies preferring to allow returns of unopened goods only. Some will accept opened goods for partial refunds or store credit. But HumanN offers 90 days to try its products and get a full refund (minus shipping costs) if you aren’t happy. Compared to other top NO boosters, that’s very customer-friendly.
Best budget pick and best novel ingredient
Image by Innerbody Research
Bulk Supplements is typically a safe bet if you're looking for simple products that won’t cost you too much money. It’s consistently one of our top picks for budget-conscious individuals, and its product quality rarely suffers for the cost difference. There are some sacrifices you’ll make by choosing it over another brand, but those might be well worth it to you.
The catalog of supplements this company offers is immense, but there are three particular products we want to highlight as good options for NO production:
Given the well-documented ability of L-arginine to affect NO production, this is the best way to go if you’re looking for a low-cost, single-ingredient approach. The L-citrulline is a bit more expensive and the L-norvaline even more so, though all three cost far less per serving than competing products.
What you sacrifice when you go with Bulk Supplements is a little bit of convenience. The bags in which it ships its products are less convenient means of storage than the containers you get from others. For one thing, if you’ve ever opened a bag of supplement powder, you know how easy it is for small plumes of powder to go airborne as the bag opens. Whether you keep using the bag or instead opt to transfer the powder to a different container, you can easily lose some of the product in a mini dust cloud.
And they don’t come with scoops of any kind. To measure out a 400mg serving of L-norvaline, you need a kitchen scale that’s sensitive to 1/10 of a gram. Those can be hard to find. In fact, our testing team resorted to a jewelry scale to measure the powder. These scales are extremely accurate, but they have low maximum weight thresholds, and the glass we were using (without water in it) exceeded this point. That meant we had to pour the powder into a smaller cup so that we could transfer it to the glass before adding water and mixing.
These ingredients mix incredibly well into water. After a small amount of stirring, the liquid appeared nearly as clear as it did before adding the powders. Of the three, the L-norvaline had the least noticeable flavor, while the other two added just a hint of bitterness. Something as simple as a dash of salt or lemon juice would make any of these ingredients undetectable to all but the most sensitive palates.
Since we’re recommending three different products from Bulk Supplements, each of which is eligible for a small 5% savings with a subscription, we thought it’d be easier to get a sense of your potential costs with a handy chart. L-Arginine and L-citrulline are available in amounts ranging from 100g-25kg, while L-norvaline is available in amounts from 10g-25kg.
For simplicity’s sake, we’ll display the prices for amounts similar to those provided for other companies’ products in the chart below:
One-time purchase | Subscription | |
---|---|---|
L-Arginine, 250g | $15.96 | $15.16 |
L-Arginine, 500g | $21.96 | $20.86 |
L-Citrulline DL-malate, 250g | $17.96 | $17.06 |
L-Citrulline DL-malate, 500g | $25.96 | $24.66 |
L-Norvaline, 250g | $41.96 | $39.86 |
L-Norvaline, 500g | $67.96 | $64.56 |
With a free shipping threshold of $59, you’d have to get at least one order of L-arginine (5kg), L-citrulline DL-malate (5kg), or L-norvaline (500g) to qualify. Otherwise, you’ll pay $9 per order.
Bulk Supplements has an odd 30-day return policy. It accepts opened products, which is more than we can say for Type Zero, but its refund on opened goods is limited to the cost of the smallest available quantity of a given product. For example, if you spent $68 on a 500g pouch of L-norvaline and decided to return it, you could only get back the cost of a 10g pouch, which is $13, losing you $55 in the process. This is pretty strict.
Given the ability for these supplements to work on an acute basis, it might be wisest to use Bulk Supplements as a way to try small quantities of each. If you buy the lowest possible amount available, you can fully protect your investment if it doesn’t seem to work for you.
Most potent formula
Image by Innerbody Research
Gorilla Mode Nitric is a product by Gorilla Mind, a company offering multiple products for workout support, cognition, and general wellness. Several of its products include ingredients that can boost nitric oxide, but Gorilla Mode Nitric is its most potent offering. The mixture is designed as a pre-workout, and like Type Zero’s pre-workout, it’s free of stimulants. This particular choice in its formulation may be safest, considering that Gorilla Mode Nitric contains creatine, an ingredient shown to improve muscle and aerobic performance; studies paint quite a murky picture about creatine and caffeine taken together, with some studies indicating caffeine may dull the positive effects of the creatine.19 24
The list of ingredients is long, and its doses are impressive, so let’s take a quick look at it:
As you can see, the doses of L-citrulline, betaine, and creatine align with much of the clinical research that supports their use. But creatine typically requires a loading dose, and the other ingredients in Gorilla Mode Nitric make it a poor choice for loading. If you want to load up on creatine before using this product as your pre-workout, you should check out some additional information on creatine in our comprehensive guide.
Image by Innerbody Research
In the same way that the “healthy” taste of HumanN SuperBeets Sport might turn some people off, the folks who enjoy it might cringe at the sweetness of Gorilla Mode Nitric. There’s no shortage of flavors to choose from, but all of them are flavored artificially and sweetened with sucralose. The result, in our opinion, is a cloyingly sweet, almost candy-like beverage that is not the most enjoyable unless you really like sweet beverages.
Here’s a list of available flavors of Gorilla Mode Nitric, along with helpful descriptions, as these names sometimes fail to tell you what each is meant to taste like:
Gorilla Mode Nitric mixes with water extremely well, which is good considering that the strength of its flavors prohibits you from adding it to just about anything else.
You can save on Gorilla Mode Nitric by buying in bulk or signing up for automatic delivery. Here’s how the pricing breaks down:
Single tub | Three-tub discount | |
---|---|---|
One-time purchase price | $59.99 | $169.97 |
One-time purchase cost per tub | $59.99 | $56.66 |
Subscription price | $53.99 | $152.97 |
Subscription cost per tub | $53.99 | $50.99 |
Shipping from Gorilla Mind is only free on orders over $150, which is the highest free shipping threshold of the products in our guide (excluding Type Zero, which never offers free shipping). The return policy here only accepts unopened products for a period of 30 days. This isn’t out of step with much of the competition, but it still pales in comparison to HumanN’s 90-day money-back guarantee.
There are several reasons a person may wish to increase their nitric oxide levels, and depending on your reasons, there may be alternative strategies that are superior to or can work in conjunction with NO-boosting supplements.
One of the most common reasons that men want to increase nitric oxide is to help with erectile performance issues. Increasing NO can improve erectile strength by increasing blood flow to the penis, but there are other factors at play here, including the activity of phosphodiesterase-5 (PDE-5). PDE-5 is largely responsible for breaking down cGMP (cyclic guanosine 3’,5’-monophosphate), an enzyme your body releases in response to arousal that’s key to achieving and sustaining an erection.
Prescription medications like Viagra and Cialis are PDE-5 inhibitors that boast well-established profiles for safety and efficacy.11 Taking these in conjunction with an NO booster may be hazardous, as it can cause an unsafe drop in blood pressure. If you speak to your doctor about getting an ED prescription, make sure to mention any NO boosters or other supplements you may be taking.
You can learn all about these medications in our guide to the best ED treatments.
Aside from medication or supplementation, there are several lifestyle adjustments you can make to increase nitric oxide levels in your body naturally. These include:
Many foods contain nitric oxide, but leafy green vegetables are the most common source. Some vegetables and other foods that increase nitric oxide levels include:
Regular exercise stimulates nitric oxide production and can also help protect your body from cardiovascular and immune system issues.23
Sources
Innerbody uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Bescós, R., Sureda, A., Tur, J. A., & Pons, A. (2012). The effect of nitric-oxide-related supplements on human performance. Sports Medicine (Auckland, N.Z.), 42(2), 99–117.
National Institutes of Health. (2022, June 2). Dietary Supplements for Exercise and Athletic Performance Fact Sheet for Health Professionals. U.S. Department of Health and Human Services.
Viribay, A., Burgos, J., Fernández-Landa, J., Seco-Calvo, J., & Mielgo-Ayuso, J. (2020). Effects of Arginine Supplementation on Athletic Performance Based on Energy Metabolism: A Systematic Review and Meta-Analysis. Nutrients, 12(5).
Sunderland, K. L., Greer, F., & Morales, J. (2011). VO2max and ventilatory threshold of trained cyclists are not affected by 28-day L-arginine supplementation. Journal of Strength and Conditioning Research, 25(3), 833–837.
Gonzalez, A. M., & Trexler, E. T. (2020). Effects of Citrulline Supplementation on Exercise Performance in Humans: A Review of the Current Literature. Journal of Strength and Conditioning Research, 34(5), 1480–1495.
Pérez-Guisado, J., & Jakeman, P. M. (2010). Citrulline malate enhances athletic anaerobic performance and relieves muscle soreness. Journal of Strength and Conditioning Research, 24(5), 1215–1222.
Kukadia, S., Dehbi, H., Tillin, T., Coady, E., Chaturvedi, N., & Hughes, A. D. (2019). A Double-Blind Placebo-Controlled Crossover Study of the Effect of Beetroot Juice Containing Dietary Nitrate on Aortic and Brachial Blood Pressure Over 24 h. Frontiers in Physiology, 10.
Bonilla Ocampo, D. A., Paipilla, A. F., Marín, E., Vargas-Molina, S., Petro, J. L., & Pérez-Idárraga, A. (2018). Dietary Nitrate from Beetroot Juice for Hypertension: A Systematic Review. Biomolecules, 8(4).
De, A., Singh, M. F., Singh, V., Ram, V., & Bisht, S. (2016). Treatment effect of l-Norvaline on the sexual performance of male rats with streptozotocin induced diabetes. European Journal of Pharmacology, 771, 247-254.
Polis, B., Gilinsky, M. A., & Samson, A. O. (2019). Reports of L-Norvaline Toxicity in Humans May Be Greatly Overstated. Brain Sciences, 9(12).
Wang, L., Zhao, M., Liu, W., Li, X., Chu, H., Bai, Y., Sun, Z., Gao, C., Zheng, L., & Yang, J. (2018). Association of betaine with blood pressure in dialysis patients. The Journal of Clinical Hypertension, 20(2), 388-393.
Olthof, M. R., van Vliet, T., Boelsma, E., & Verhoef, P. (2003). Low Dose Betaine Supplementation Leads to Immediate and Long Term Lowering of Plasma Homocysteine in Healthy Men and Women. The Journal of Nutrition, 133(12), 4135-4138.
Camic, C. L., Housh, T. J., Mielke, M., Zuniga, J. M., Hendrix, C. R., Johnson, G. O., Schmidt, R. J., & Housh, D. J. (2010). The effects of 4 weeks of an arginine-based supplement on the gas exchange threshold and peak oxygen uptake. Applied Physiology, Nutrition, and Metabolism, 35(3), 286–293.
Houston, M., & Hays, L. (2014). Acute Effects of an Oral Nitric Oxide Supplement on Blood Pressure, Endothelial Function, and Vascular Compliance in Hypertensive Patients. The Journal of Clinical Hypertension, 16(7), 524-529.
Davies, K. P. (2015). Development and therapeutic applications of nitric oxide releasing materials to treat erectile dysfunction. Future Science OA, 1(1).
Lansley, K. E., Winyard, P. G., Bailey, S. J., Vanhatalo, A., Wilkerson, D. P., Blackwell, J. R., Gilchrist, M., Benjamin, N., & Jones, A. M. (2011). Acute dietary nitrate supplementation improves cycling time trial performance. Medicine and Science in Sports and Exercise, 43(6), 1125–1131.
Bescós, R., Rodríguez, F. A., Iglesias, X., Ferrer, M. D., Iborra, E., & Pons, A. (2011). Acute administration of inorganic nitrate reduces VO(2peak) in endurance athletes. Medicine and Science in Sports and Exercise, 43(10), 1979–1986.
Steenbergen, L., Sellaro, R., Hommel, B., & Colzato, L. S. (2015). Tyrosine promotes cognitive flexibility: evidence from proactive vs. reactive control during task switching performance. Neuropsychologia, 69, 50–55.
Trexler, E. T., & Smith-Ryan, A. E. (2015). Creatine and Caffeine: Considerations for Concurrent Supplementation. International Journal of Sport Nutrition and Exercise Metabolism, 25(6), 607–623.
Morita, M., Hayashi, T., Ochiai, M., Maeda, M., Yamaguchi, T., Ina, K., & Kuzuya, M. (2014). Oral supplementation with a combination of l-citrulline and l-arginine rapidly increases plasma l-arginine concentration and enhances NO bioavailability. Biochemical and Biophysical Research Communications, 454(1), 53-57.
Rytlewski, K., Olszanecki, R., Korbut, R. and Zdebski, Z. (2005), Effects of prolonged oral supplementation with l-arginine on blood pressure and nitric oxide synthesis in preeclampsia. European Journal of Clinical Investigation, 35: 32-37.
Andersson, E. (2018). PDE5 inhibitors – pharmacology and clinical applications 20 years after sildenafil discovery. British Journal of Pharmacology, 175(13), 2554-2565.
Tsukiyama, Y., Ito, T., Nagaoka, K., Eguchi, E., & Ogino, K. (2017). Effects of exercise training on nitric oxide, blood pressure and antioxidant enzymes. Journal of Clinical Biochemistry and Nutrition, 60(3), 180-186.
Elosegui, S., López-Seoane, J., Martínez-Ferrán, M., Pareja-Galeano, H. (2022). Interaction between caffeine and creatine when used as concurrent ergogenic supplements: A systematic review. International Journal of Sport Nutrition and Exercise Metabolism, 32(4), 285-295.
Saat, M., Singh, R., Sirisinghe, R. G., & Nawawi, M. (2002). Rehydration after exercise with fresh young coconut water, carbohydrate-electrolyte beverage and plain water. Journal of Physiological Anthropology and Applied Human Science, 21(2), 93–104.
Gandhi, M., Aggarwal, M., Puri, S., & Singla, S. K. (2013). Prophylactic effect of coconut water (Cocos nucifera L.) on ethylene glycol induced nephrocalcinosis in male wistar rat. International Braz J Urol : Official Journal of the Brazilian Society of Urology, 39(1), 108–117.
Gonzalez, A. M., Townsend, J. R., Pinzone, A. G., & Hoffman, J. R. (2023). Supplementation with Nitric Oxide Precursors for Strength Performance: A Review of the Current Literature. Nutrients, 15(3), 660.
Jones, A. (2016). Dietary Nitric Oxide Precursors and Exercise Performance. Sports Science Exchange, 29(156), 1-6.
Ahmad, A., Dempsey, S. K., Daneva, Z., Azam, M., Li, N., Li, L., & Ritter, J. K. (2018). Role of Nitric Oxide in the Cardiovascular and Renal Systems. International Journal of Molecular Sciences, 19(9).